Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/738

634 634 EDWARD HULL ON THE CLASSIFICATION Stage E. Gannister Beds. — Shales &c. with the " Slaty-band " ironstone with marine shells ; Lingula mytiloides, Discina nitida, Axinus deltoidcs, Mur- chisonia, Conularia quadrisulcata, Nautilus*. Stage D. 340 to 400 feet. — " Moorstone-Rock " series (Roslin sandstones) with accompanying beds down to the Garnkirk Limestone. Fossils marine. Stage C (?). Yore-dale Beds.—(b) " Upper Limestone Series" of Scottish geo- logists, including the Garnkirk-limestone. (Marine and Estuarine beds.) 290 feet thick. (a) " Lower Coal and Ironstone Series." Shales, coals, and black-band ironstones with fish, Entomostraca (Carbonid), &c. (Estuarine and freshwater.) 160 feet. Stage B. — "Lower Limestone Series," including the Roman Camp and Gil- inerton Limestones (marine), 522 feet. Stage A. — " Calciferous Sandstone Series " in two groups, the upper (b) variable in thickness and extent, consisting of white and grey sandstones, bitumi- nous shales and limestones with cyprids, fish, &c. (Burdie-house limestone near Edinburgh) ; the lower (a) of dull reddish sandstones, shales, conglo- merates, and beds of " Cornstone " (Plants &c). Mr. J. Young, of the Himterian Museum, is of opinion that the lower division of Stage C is of freshwater origin. Marine shells are absent, while Entomostraca of the genus Garbonia are abundant in the shales ; of these, ten species have been determined by Messrs. Rupert Jones and Kirkby. In the above section of the Scottish strata it will be observed that I have ventured to insert two groups not hitherto recognized — ■ namely, Stages E and C, representing the " Gannister Beds " and " Yoredale Series " of England respectively. I have never been able clearly to understand why these two groups have failed to be admitted into the classification of the North- British Carboniferous series, as it was difficult to conceive that groups which in North Lancashire and Yorkshire attain considerable proportions (about 2000 and 3000 feet respectively) should have altogether thinned away, or disappeared north of the Border Land. During the debate, however, which took place upon the reading of my paper at Glasgow, Mr. John Young, F.G.S., suggested that if representatives of the Gannister-beds were to be found in Scotland at all, it would be in the horizon of " the Slaty black-band ironstone " series, which is rich in marine forms, and lies immediately above the "Millstone-Grit series." The fossils which are above enumerated have been collected by Dr. W« Grossart, in the parish of Shotts : and John Young, F.G.S., of the Himterian Museum, Glasgow. The following are the fossil forms from the Slaty -band Ironstone given in the Memoirs of the Geol. Survey of Scotland from Lanarkshire — Lingula myti- loides, L. squamiformis, Anthracosia subconstricta, A. acuta, A. aquilina. (Ex- planation of Sheet 23, p. 89-90.) Those from the Millstone Grit are — Lingula mytiloides, L. squamiformis, Orf.his resupmata, Streptorhynchus crenistria, Naticopsis, sp. inc. (Ibid. p. 89.)
 * Determined by Dr. W. Grossart, and communicated to the author by Mr.